\newcommand{\email}[1]{\texttt{#1}}

% acronyms, printed in small caps
\newcommand{\acro}[1]{\textsc{#1}}

% keywords, printed in monospace type
\newcommand{\key}[1]{\texttt{#1}}

% placeholder for an identifier in syntax definitions
\newcommand{\id}[1]{\textit{identifier}$_{#1}$}

% placeholder for an expression in syntax definitions
\newcommand{\expr}[1]{\textit{expression}$_{#1}$}

% placeholder for a sequence of statements in syntax definitions
\newcommand{\statements}[1]{\textit{statements}$_{#1}$}

% space at the beginning of an indented line of syntax
\newcommand{\codeindent}{\hspace*{3em}}

% syntax definition
\newenvironment{syntax}%
{%
\begin{list}{\textbf{Syntax:}}%
{%
\setlength{\leftmargin}{6.8em}%
\setlength{\labelsep}{3em}%
\setlength{\labelwidth}{4em}%
}%
\item{}%
}%
{\end{list}}% end newenvironment{syntax}

% example block
\newenvironment{example}%
{%
\begin{list}{}%
{%
\setlength{\leftmargin}{6.8em}%
\setlength{\labelsep}{3em}%
\setlength{\labelwidth}{4em}%
}%
\item{}%
}%
{\end{list}}% end newenvironment{example}

